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PATENTED FEB. 9, 1904. D. G. GRAY.

METHOD OF BUILDING CONCRETE WALLS, &0.

APPLICATION FILED JUNE 24. 1903.

[77 Var/7021' Cl/Zarwqyr.

UNITE STATES Patented February 9, 1904.

PATENT OFFICE.

DAVID G. GRAY, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO. MoGrAW ANDGRAY, OF PHILADELPHIA, PENNSYLVANIA, A FIRM.

METHOD OF BUILDING CONCRETE WALLS, 81.0.

SPECIFICATION forming part of Letters Patent No. 751,789, dated February9, 1904.

Application filed June 24, 1903. Serial No. 162,839. (No model.)

To all whom it may concern:

Be it known that I, DAVID G. GRAY, a citizen of the United States,residing in the city and county of Philadelphia, State of Pennsylvania,have invented a new and useful Improvement in Methods of BuildingConcrete Nails, &c., of which the following is a specification.

My invention relates to an improvement in the method of buildingconcrete walls, piers,

or abutments. 7

It comprises means for joining the moldboards in such a manner that asthe wall increases in height the lower boards may be released and reusedabove.

It further comprises a wooden or metal molding on the lower edge of eachboard and overhanging said edge and similar moldings placed verticallyat a desired distance apart, which molds form recesses in the face ofthe concrete representing any system of ashler or broken-range jointingdesired.

It further consists of novel features of construction, all as will behereinafter described.

Figure 1 represents a vertical section of the mold boards or forms usedin the practice of my invention as they appear when set in position foruse. Fig. 2 represents a partial rear elevation'of one of themold-boards. Fig. 3 represents a partial front elevation of the same.Fig. at represents, on an enlarged scale, a partial cross-section of twoof the boards. Fig. 5 represents in perspective a finished concretewall, showing ashler jointing. Fig. 6 represents a pair of the wedgesemployed.

Similar letters of reference indicate corresponding parts in thefigures.

Referring to the drawings, A designates the timber studding or framing,which is first erected at the required distance from the faces of thewall to be built.

B designates mold-boards, which may be of wood heavily coated withlinseed-oil or the like to prevent absorption of moisture.

U designates wooden battens screwed to the back of the boards B toprevent warping.

D D represent wedges inserted between the frame A and battens C.

E represents a molding attached to the boards B at their lower edge andvertically at any desired distances apart.

F represents a wall having recesses Gr imitating ashler jointing.

The operation is as follows: Frames A having been set up and properlybraced parallel to each other on each side of the wall to be built, rowsof boards B are placed therebetween facing each other and supported fromthe frames A by wedges D D. The concrete mass is then placed between theboards B and properly tamped, one or more (usually one) additional rowof boards being superposed on the first as the work progresses. It willbe seen from Fig. 4 that the joint between the boards is broken and thatthe bead E, secured at the lower edge of each board above the first,tends to keep the boards in proper position in relation to each other.As the wall solidifies the lower boards may be removed and placed at thetop of the structure for reuse, as desired, and any defects remediedwhile concrete is fresh. To remove the boards, it is only necessary towithdraw the wedges D D. It will be evident from the above that greateconomy is effected in the number of boards required.

It will be evident that various changes may be made by those skilled inthe art which may come within the scope of my invention,

and I do not therefore desire to be limited in every instance to theexact construction herein shown and described.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. A device for molding a concrete wall which comprises a plurality ofmold-boards against which the concrete mass is placed and means forsupporting said boards one above another, the adjacent edges of saidboards being covered by a projecting molding secured to one of saidparts and adapted to form arecess in the wall.

2. In a device for molding a concrete wall, a mold-board having amolding secured to its face adjacent and overhanging one of its edges,whereby said molding is adapted to overlap 5 an adjoining mold-board.

3. In a device for molding a concrete Wall, a plurality of mold -boardshaving broken joints and moldings secured to the face of each adjacentand overhanging one of its edges, whereby said molding ,is adapted tooverlap I an adjoining mold-board.

DAVID Gr. GRAY.

Witnesses:

R BERT F. MoGAw, ANDREW GRAY.

